Chlorate-containing stabilizer system with nitrogen-containing synergists for stabilizing halogen-containing polymers

ABSTRACT

The invention relates to stabilizer systems, containing at least: a) a perchlorate salt; b) at least one or more compounds from the group consisting of carbamides, indole derivatives and enamines of formula (I), wherein n=1 or 2 and X═O or NR 1 ; n=3-6 and X═O; R 1 ═H, C 1 -C 4 -alkyl, C 2 -C 6 -alkenyl, C 6 -C 10 -aryl, C 7 -C 18 -alkaryl or C 7 -C 18 -aralkyl; R 2  (if n=1)=C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl or aryl, preferably phenyl, optionally substituted with up to 3 hydroxy, C 1 -C 4 -alkoxy or C 1 -C 9 -alkyl; or R 2  (if n=2-6)=linear or branched C 1 -C 22 -alkylene, optionally interrupted by one or more O or S atoms, wherein R 2  (if n=3) can also be a C 2 -C 3 -alkyl trisubstituted isocyanurate; if X═NH R 2  can also be H. Said stabilizer systems are suitable for stabilizing halogen-containing polymers, more particularly PVC.

[0001] The invention relates to stabilizer systems encompassing at leastone perchlorate salt and at least one or more compounds from the groupsconsisting of the enamines, indoles and ureas, which are suitable forstabilizing halogen-containing polymers.

[0002] A halogen-containing polymer, such as PVC, may be stabilized byany of a large number of additives. Compounds of lead, of barium, and ofcadmium are particularly well suited to this purpose, but are nowadayscontroversial for environmental reasons or because of their heavy metalcontent (cf. “Kunststoffadditive”[Plastics Additives], R. Gächter and H.Müller, Carl Hanser Verlag, 3rd Edition 1989, pp. 303-311 (see also 4thEdition 2001); and “Kunststoff Handbuch PVC” [Plastics Handbook PVC],Volume 2/1, W. Becker and D. Braun, Carl Hanser Verlag, 2nd Edition,1985, pp. 531-538; and Kirk-Othmer: “Encyclopedia of ChemicalTechnology”, 4th Edition, 1994, Vol. 12, Heat Stabilizers, pp.1071-1091).

[0003] There is therefore a continuing search for effective stabilizersand stabilizer systems which are free from lead, barium and cadmium.

[0004] It has now been found that systems made from at least one or morecompounds from the groups consisting of the enamines, indoles and ureas,and from at least one perchlorate salt, are particularly highly suitablefor stabilizing chlorine-containing polymers, in particular PVC.

[0005] This is surprising, since mixtures made from aminocrotonic estersand epoxy compounds exhibit “non-specific” effects. This is seen by wayof example in Table 1B, from which it is apparent that the use of theorganic stabilizer 2-phenylindole and of the free-radical scavengerWessalith (mixture 1/3) reduces the level of stabilization to anunexpectedly drastic extent when compared with the sole use of theorganic stabilizer (mixture 1/1), but the use of the organic stabilizerand of the free-radical scavenger combined with the salt sodiumperchlorate as stabilizer (mixture 1/4) results in a surprising,synergistic rise in stability.

[0006] The invention accordingly provides stabilizer systems comprisingat least

[0007] a) one perchlorate salt and

[0008] b) at least one or more enamines and/or indole and/or ureas

[0009] where the enamines have the formula (I)

[0010] where

[0011] n=1 or 2 and X═O or NR¹,

[0012] n=3-6 and X═O;

[0013] R¹═H, C₁-C₄-alkyl, C₂-C₆-alkenyl, C₆-C₁₀-aryl, C₇-C₁₈-alkaryl orC₇-C₁₈-aralkyl;

[0014] R² (for n=1)=C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl or aryl, preferablyphenyl, where appropriate substituted with up to 3 hydroxyl,C₁-C₄-alkoxy or C₁-C₉-alkyl; or

[0015] R² (for n=2-6)=linear or branched C_(n)-C₂₂-alkylene, whereappropriate interrupted by one or more O atoms or S atoms, where R² (forn=3) may also be C₂-C₃-alkyl-trisubstituted isocyanurate;

[0016] and if X═NH, R² may also be H, and

[0017] where the indoles have the general formula (II)

[0018] where

[0019] m=0, 1, 2 or 3;

[0020] R³═H, C₁-C₁₈-alkyl, C₂-C₁₈-alkenyl, C₆-C₁₀-aryl or

[0021] C₇-C₂₄-alkaryl, C₇-C₁₀-aralkyl or C₁-C₄-alkoxy;

[0022] R⁴, R⁵═H, C₁-C₄-alkyl, or C₁-C₄-alkoxy; and

[0023] where the ureas have the general formula (III)

[0024] where

[0025] Y═O, S or NH;

[0026] R⁶, R⁷, R⁸ and R⁹, independently of one another, are H,C₁-C₁₈-alkyl, where appropriate substituted with hydroxyl groups and/orC₁-C₄-alkoxy groups, C₂-C₁₈-alkenyl, C₆-C₁₀-aryl, where appropriatesubstituted with up to 3 hydroxyl and/or C₁-C₄-alkyl/alkoxy groups,C₇-C₂₀-alkaryl or C₇-C₁₀-aralkyl, and two substituents from R⁶ to R⁹ mayalso form a ring, and the urea used may also be a dimerized ortrimerized urea, e.g. biuret, triuret or 1,3,5-tris(hydroxyalkyl)isocyanurate;

[0027] and possible reaction products of these.

[0028] Examples of the enamines of the general formula (I) (X═O or NH)are compounds where R¹=hydrogen, methyl, ethyl, n-propyl, iso-propyl,n-butyl, iso-butyl, sec-butyl, tert-butyl, allyl, phenyl or benzyl, R²(for n=1)=1-octyl, 2-ethylhexyl, n-decyl, n-dodecyl, n-tetradecyl,n-hexadecyl, n-octadecyl, oleyl, dihydroxystearyl, trihydroxystearyl orricinolyl, R² (for n=2)=derived from the corresponding R²—(OH)₂ compoundethanediol, 1,4-butanediol, 1,3-butanediol, 2,3-butanediol,1,6-hexanediol, neopentylene glycol, dialkylene glycol, trialkyleneglycol, tetraalkylene glycol, pentaalkylene glycol, hexaalkylene glycol,preferably where alkylene=ethylene, propylene or butylene,thio(dialkylene glycol), dithio(trialkylene glycol),trithio(tetraalkylene glycol), tetrathio-(pentaalkylene glycol),pentathio(hexaalkylene glycol), preferably where alkylene=ethylene, orneopentylene glycol, R² (for n=3)=derived from the correspondingR²—(OH)₃ compound glycerol, tris(hydroxyethyl) isocyanurate,tris(hydroxypropyl) isocyanurate, trimethylolethane ortrimethylolpropane, R² (for n=4)=derived from the corresponding R²—(OH)₄compound erythritol, xylitol, pentaerythritol, bis(trimethylol)ethane orbis(trimethylol)propane, R² (for n=6)=derived from the correspondingR²—(OH)₆ compound sorbitol, mannitol or dipentaerythritol.

[0029] Preference is given to enamines where R¹=methyl or phenyl.

[0030] The enamines of the general formula (I) may be prepared by knownmethods, by acylating and aminating the corresponding R²—OH or R²—NH₂compound (see inter alia DE-C 1,544,768).

[0031] Preference is given to β-aminocrotonic ester compounds andβ-aminocinnamic ester compounds of the general formula (I). Particularlypreferred compounds of the general formula (I) are 1,4-butanediolbis(β-aminocrotonate), 2,3-butanediol bis(β-aminocrotonate),1,2-dipropylene glycol bis(β-aminocrotonate) and thio (diethyleneglycol) bis(β-aminocrotonate).

[0032] Examples of the indoles of the general formula (II) are compoundswhere R³=methyl, ethyl, propyl, phenyl, allyl or benzyl, and R⁴=methyl,ethyl, propyl or butyl. Preference is given to compounds of the generalformula (II) where R³=phenyl or phenyllauryl and R⁴=hydrogen.

[0033] Compounds of the general formula (II) may be prepared by knownmethods (see, inter alia, DE-C 862,512). Examples of these compounds areindole, 2-phenylindole, 2-phenyllaurylindole, 2-allylindole,2-benzylindole, 2-phenylethylindole, 2-methylindole, 2-ethylindole,2-propylindole, 2-butylindole and 2-phenyl-5-methylindole. Preference isgiven to 2-phenylindole and 2-phenyllaurylindole, and also2-methylindole and 2-ethylindole.

[0034] 2-Phenylindole is a particularly preferred compound of thegeneral formula (II).

[0035] Examples of ureas of the general formula (III) are compoundswhere R⁶, R⁷, R⁸ or R⁹=hydrogen, methyl, phenyl, benzyl, phenethyl,hydroxyethyl, hydroxypropyl or hydroxybutyl. Preference is given tocompounds of the general formula (III) where R⁶, R⁷, R⁸ or R⁹=phenyl orbenzyl.

[0036] Compounds of the general formula (III) may be prepared by knownmethods (see, inter alia, DE-C 746,081, Italian Patent 386,750).Examples of these compounds are urea, N,N′-diphenylthiourea,N,N′-diphenylurea, N,N′-dibenzylthiourea, N,N′-dibenzylurea,N,N′-dimethylthiourea, N-benzylthiourea, N,N-dibenzylthiourea andN,N,N′-tribenzylthiourea, N,N′-diphenylguanidine, biuret and triuret.Preference is given to examples having phenyl and, respectively,ethylene- and propyleneurea, and also N,N′-bis(hydroxyethyl)urea andtris(hydroxyethyl/propyl) isocyanurate.

[0037] Particularly preferred compounds of the general formula (III) areN,N′-diphenylthiourea and N-phenylurea.

[0038] The perchlorate salts are known to the person skilled in the art.Examples of these are those of the formula M(ClO₄)_(n), where M is Li,Na, K, Mg, Ca, Sr, Ba, Zn, Al, La or Ce; and n is 1, 2 or 3, dependingon the valency of M. Use may be made of these perchlorate salts in theirvarious commonly encountered forms, e.g. as salt or as solution in wateror in an organic solvent, on their own or absorbed on a support, such asPVC, Ca silicate, zeolites or hydrotalcites. Examples of these areperchlorate salts complexed or dissolved using alcohols (polyols,cyclodextrins) or using ether alcohols or ester alcohols or crownethers. EP 0 394 547, EP 0 457 471 and WO 94/24200 describe otherembodiments.

[0039] It is preferable to use sodium perchlorate or potassiumperchlorate.

[0040] The invention also provides combinations of the stabilizersystems encompassing at least one perchlorate salt and at least one ormore compounds from the groups consisting of the compounds of thegeneral formula (I) or (II) or (III) with at least one or more otherconventional additives or stabilizers. Preference is given to polyolsand/or disaccharide alcohols, glycidyl compounds, hydrotalcites,zeolites (alkali metal aluminosilicates and alkaline earth metalaluminosilicates), fillers, metal soaps, alkali metal and alkaline earthmetal compounds, such as oxides and hydroxides, lubricants,plasticizers, phosphites, pigments, epoxidized fatty esters and otherepoxy compounds, antioxidants, UV absorbers and light stabilizers,optical brighteners and blowing agents. Particular preference is givento epoxidized soya oils, alkaline earth metal or aluminium soaps andphosphites.

[0041] Particular preference is given to those components which aresuitable for producing physiologically non-hazardous products.

[0042] Examples of additional components of this type are listed andexplained at a later stage below (cf. “Handbook of PVC Formulating” byE. J. Wickson, John Wiley & Sons, New York, 1993 and Synoptic DocumentNo. 7, Scientific Committee for Food (SCF)—EU).

[0043] Polyols and Disaccharide Alcohols

[0044] Examples of possible compounds of this type are: glycerol,pentaerythritol, dipentaerythritol, tripentaerythritol,trimethylolethane, bis(trimethylolpropane), polyvinyl alcohol,bis(trimethylolethane), trimethylolpropane, sugars, sugar alcohols.

[0045] Of these, preference is given to pentaerythritol,trimethylolpropane, sorbitol and the disaccharide alcohols such asMalbit, lactitol and cellobiitol, and also Palatinit.

[0046] It is also possible to use polyol syrups, such as sorbitol syrup,mannitol syrup and maltitol syrup. Examples of the amounts of thepolyols used are from 0.01 to 20 parts by weight, advantageously from0.1 to 20 parts by weight and in particular from 0.1 to 10 parts byweight, based on 100 parts by weight of PVC.

[0047] Glycidyl Compounds

[0048] These contain the glycidyl group

[0049] bonded directly to carbon, oxygen, nitrogen or sulphur atoms,either where both of R₁ and R₃ are hydrogen, R₂ is hydrogen or methyland n=0 or where R₁ and R₃ together are —CH₂—CH₂— or —CH₂—CH₂—CH₂—, R₂then being hydrogen and n being 0 or 1.

[0050] It is preferable to use glycidyl compounds having two functionalgroups. However, it is also possible in principle to use glycidylcompounds having one, three or more functional groups.

[0051] Use is predominantly made of diglycidyl compounds having aromaticgroups.

[0052] The amounts used of the terminal epoxy compounds are preferablyat least 0.1 part, preferably from 0.1 to 50 parts by weight,advantageously from 1 to 30 parts by weight and in particular from 1 to25 parts, based on 100 parts by weight of PVC.

[0053] Hydrotalcites

[0054] The chemical composition of these compounds is known to theskilled worker, e.g. from the patents DE 3 843 581, U.S. Pat. No.4,000,100, EP 0 062 813 and WO 93/20135. Compounds from the hydrotalciteseries may be described by the following general formula

M²⁺ _(1-x)M³⁺ _(x)(OH)₂ (A^(b−))_(x/b)·d H₂O,

[0055] where

[0056] M²⁺=one or more of the metals selected from the group consistingof Mg, Ca, Sr, Zn and Sn

[0057] M³⁺=Al or B,

[0058] A^(n) an anion of valency n, b is a number from 1-2,

[0059] 0<x<0.5,

[0060] d is a number from 0-20.

[0061] Preference is given to compounds with

[0062] A^(n)=OH⁻, ClO₄ ⁻, HCO₃ ⁻, CH₃COO⁻, C₆H₅COO⁻, CO₃ ²⁻, (CHOHCOO)₂²⁻, (CH₂COO)₂ ²⁻, CH₃CHOHCOO⁻, HPO₃ ⁻ or HPO₄ ²⁻;

[0063] Examples of hydrotalcites are

[0064] Al₂O₃.6MgO.CO₂.12H₂O (i), Mg_(4.5)Al₂(OH)₁₃.CO₃.3.5H₂O (ii),4MgO.Al₂O₃.CO₂.9H₂O (iii), 4MgO.Al₂O₃.CO₂.6H₂O,ZnO.3MgO.Al₂O₃.CO₂.8-9H₂O and ZnO.3MgO.Al₂O₃.CO₂.5-6H2O.

[0065] Very particular preference is given to types (i), (ii) and (iii).

[0066] Zeolites (aluminosilicates of Alkali Metals and/or of AlkalineEarth Metals)

[0067] These may be described by the following general formulaM_(x/n)[(AlO₂)_(x)(SiO₂)_(y)].wH₂O, where n is the charge on the cationM;

[0068] M is an element of the first or second main group, such as Li,Na, K, Mg, Ca, Sr or Ba;

[0069] y:x is a number from 0.8 to 15, preferably from 0.8 to 1.2; and

[0070] w is a number from 0 to 300, preferably from 0.5 to 30.

[0071] Examples of zeolites are sodium aluminosilicates of the formulae

Na₁₂Al₁₂Si₁₂O₄₈.27 H₂O [zeilite A], Na₆Al₆Si₆O₂₄.2 NaX. 7.5 H₂O, X═OH,halogen, ClO₄ [sodalite]; Na₆Al₆Si₃₀O₇₂. 24 H₂O; Na₈Al₈Si₄₀O₉₆.24 H₂O;Na₁₆Al₁₆Si₂₄O₈₀.16 H₂O; Na₁₆Al₁₆Si₃₂O₉₆.16 H₂O; Na₅₆Al₅₆Si₁₃₆O₃₈₄.250H₂O [zeolite Y], Na₈₆Al₈₆Si₁₀₆O₃₈₄.264 H₂O [zeolite X];

[0072] or the zeolites which can be prepared by partial or completeexchange of the Na atoms by Li atoms, K atoms, Mg atoms, Ca atoms, Sratoms or Zn atoms, for example (Na,K)₁₀Al₁₀Si₂₂O₆₄.20 H₂O;Ca_(4.5)Na₃[(AlO₂)₁₂(SiO₂)₁₂].30 H₂O; K₉Na₃[(AlO₂)₁₂(SiO₂)₁₂].27 H₂O.

[0073] Very particular preference is given to Na zeolite A and Nazeolite P.

[0074] The hydrotalcites and/or zeolites may be used in amounts of, forexample, 0.1 to 20 parts by weight, expediently 0.1 to 10 parts byweight and in particular 0.1 to 5 parts by weight, based on 100 parts byweight of halogen-containing polymer.

[0075] Fillers

[0076] Fillers such as calcium carbonate, dolomite, wollastonite,magnesium oxide, magnesium hydroxide, silicates, china clay, talc, glassfibres, glass beads, wood flour, mica, metal oxides or metal hydroxides,carbon black, graphite, rock flour, heavy spar, glass fibres, talc,kaolin and chalk are used. Preference is given to chalk (HANDBOOK OF PVCFORMULATING, E. J. Wickson, John Wiley & Sons, Inc., 1993, pp. 393-449)and reinforcing agents (TASCHENBUCH der Kunststoffadditive [PlasticsAdditives Handbook], R. Gächter & H. Müller, Carl Hanser, 1990, pp.549-615).

[0077] The fillers may be used in amounts of preferably at least onepart by weight, for example 5 to 200 parts by weight, expediently 10 to150 parts by weight and in particular from 15 to 100 parts by weight,based on 100 parts by weight of PVC.

[0078] Metal Soaps

[0079] Metal soaps are primarily metal carboxylates, preferably ofrelatively long-chain carboxylic acids. Well-known examples of these arestearates, oleates, palmitates, ricinolates, hydroxystearates,dihydroxy-stearates and laurates, and also oleates and salts ofrelatively short-chain aliphatic or aromatic carboxylic acids, such asacetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid,sorbic acid, oxalic acid, malonic acid, maleic acid, anthranilic acid,succinic acid, glutaric acid, adipic acid, fumaric acid, citric acid,benzoic acid, salicylic acid, phthalic acids, hemimellitic acid,trimellitic acid, pyromellitic acid.

[0080] Metals which should be mentioned are: Li, Na, K, Mg, Ca, Sr, Ba,Zn, Al, La, Ce and rare earth metals. Use is frequently made ofso-called synergistic mixtures, such as barium/zinc stabilizers,magnesium/zinc stabilizers, calcium/zinc stabilizers orcalcium/magnesium/zinc stabilizers. The metal soaps may be used eitheralone or in mixtures. An overview of common metal soaps is found inUllmann's Encyclopedia of Industrial Chemistry, 5th Ed., Vol. A16(1985), pp. 361 et seq.

[0081] The metal soaps or mixtures of these may be used in amounts of,for example, 0.001 to 10 parts by weight, expediently 0.01 to 8 parts byweight, particularly preferably 0.05 to 5 parts by weight, based on 100parts by weight of PVC.

[0082] Alkali Metal and Alkaline Earth Metal Compounds

[0083] For the purposes of the present invention, these are mainly thecarboxylates of the acids described above, but also corresponding oxidesor, respectively, hydroxides or carbonates. Mixtures of these withorganic acids are also possible. Examples are LiOH, NaOH, KOH, CaO,Ca(OH)₂, MgO, Mg(OH)₂, Sr(OH)₂, Al(OH)₃, CaCO₃ and MgCO₃ (and also basiccarbonates, such as magnesia alba and huntite), and also fatty-acidsalts of Na and of K. In the case of alkaline earth carboxylates and Zncarboxylates it is also possible to use adducts of these with MO orM(OH)₂ (M=Ca, Mg, Sr or Zn), so-called “overbased” compounds. Inaddition to the stabilizers according to the invention it is preferableto use alkali metal carboxylates, alkaline earth metal carboxylatesand/or aluminium carboxylates.

[0084] Lubricants

[0085] Examples of possible lubricants are: fatty acids, fatty alcohols,montan wax, fatty acid esters, PE waxes, amide waxes, chloroparaffins,glycerol esters and alkaline earth metal soaps, and fatty ketones, andalso the lubricants, or combinations of the lubricants, listed in EP 0259 783. Stearic acid, stearic esters and calcium stearate arepreferred.

[0086] Plasticizers

[0087] Examples of organic plasticizers are those from the followinggroups and mixtures thereof:

[0088] A) Phthalates: such as preferably di-2-ethylhexyl, diisononyl anddiisodecyl phthalate, also known by the common abbreviations DOP(dioctyl phthalate, di-2-ethylhexyl phthalate), DINP (diisononylphthalate), DIDP (diisodecyl phthalate), di(^(n)C₉-C₁₂)phthalates, e.g.[sic] esters of aliphatic dicarboxylic acids, in particular esters ofadipic, azelaic or sebacic acid: preferably di-2-ethylhexyl adipate anddiisooctyl adipate.

[0089] C) Trimellitic esters, such as tri-2-ethylhexyl trimellitate,triisodecyl trimellitate (mixture), triisotridecyl trimellitate,triisooctyl trimellitate (mixture), and also tri-C₆-C₈-alkyl,tri-C₆-C₁₀-alkyl, tri-C₇-C₉-alkyl and tri-C₉-C₁₁-alkyl trimellitate.Common abbreviations are TOTM (trioctyl trimellitate, tri-2-ethylhexyltrimellitate), TIDTM (triisodecyl trimellitate) and TITDTM(triisotridecyl trimellitate).

[0090] D) Epoxy plasticizers: these are primarily epoxidized unsaturatedfatty acids, e.g. epoxidized soybean oil (as described under theepoxidized fatty esters).

[0091] E) Polymeric plasticizers: the commonest starting materials forpreparing polyester plasticizers are: dicarboxylic acids, such asadipic, phthalic, azelaic or sebacic acid; diols, such as1,2-propanediol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol,neopentyl glycol and diethylene glycol.

[0092] F) Phosphoric esters: a definition of these esters is given inthe abovementioned “Taschenbuch der Kunststoffadditive” [“PlasticsAdditives Handbook”], Chapter 5.9.5, pp. 408-412. Examples of thesephosphoric esters are tributyl phosphate, tri-2-ethylbutyl phosphate,tri-2-ethylhexyl phosphate, trichloroethyl phosphate, 2-ethylhexyldiphenyl phosphate, cresyl diphenyl phosphate, triphenyl phosphate,tricresyl phosphate and trixylenyl phosphate.

[0093] G) Chlorinated hydrocarbons (paraffins)

[0094] H) Hydrocarbons

[0095] I) Monoesters, e.g. butyl oleate, phenoxyethyl oleate,tetrahydrofurfuryl oleate and alkylsulphonates.

[0096] J) Glycol esters, e.g. diglycol benzoates.

[0097] K) Citric esters

[0098] A definition of these plasticizers and examples of the same aregiven in “Kunststoffadditive” [“Plastics Additives”], R. Gächter/H.Müller, Carl Hanser Verlag, 3rd Ed., 1989, Chapter 5.9.6, pp. 412-415,and in “PVC Technology”, W. V. Titow, 4th Ed., Elsevier Publ., 1984, pp.165-170. It is also possible to use mixtures of different plasticizers.

[0099] The plasticizers may be used in amounts of, for example, 5 to 20parts by weight, expediently 10 to 20 parts by weight, based on 100parts by weight of PVC. Rigid or semirigid PVC comprises preferably upto 10%, particularly preferably up to 5%, of plasticizer, or noplasticizer.

[0100] Pigments

[0101] Suitable substances are known to the skilled worker. Examples ofinorganic pigments are TiO₂, pigments based on zirconium oxide, BaSO₄,zinc oxide (zinc white) and lithopones (zinc sulphide/barium sulphate),carbon black, carbon black-titanium dioxide mixtures, iron oxidepigments, Sb₂O₃, (Ti,Ba,Sb)O₂, Cr₂O₃, spinels, such as cobalt blue andcobalt green, Cd(S,Se), ultramarine blue. Examples of organic pigmentsare azo pigments, phthalocyanine pigments, quinacridone pigments,perylene pigments, diketopyrrolopyrrole pigments and anthraquinonepigments. TiO₂ in micronized form is also preferred. Mixtures of variouspigments may also be used. A definition and further descriptions arefound in the “Handbook of PVC Formulating”, E. J. Wickson, John Wiley &Sons, New York, 1993.

[0102] Phosphites (Triesters of Phosphorous Acid)

[0103] Organic phosphites are known costabilizers forchlorine-containing polymers. Examples of these are trioctyl, tridecyl,tridodecyl, tritridecyl, tripentadecyl, trioleyl, tristearyl, triphenyl,tricresyl, tris(nonylphenyl), tris(2,4-tert-butylphenyl) andtricyclohexyl phosphite.

[0104] Other suitable phosphites are various mixed aryl dialkyl or alkyldiarylphosphites, such as phenyl dioctyl, phenyl didecyl, phenyldidodecyl, phenyl ditridecyl, phenyl ditetradecyl, phenyl dipentadecyl,octyl diphenyl, decyl diphenyl, undecyl diphenyl, dodecyl diphenyl,tridecyl diphenyl, tetradecyl diphenyl, pentadecyl diphenyl, oleyldiphenyl, stearyl diphenyl and dodecyl bis(2,4-di-tert-butylphenyl)phosphite.

[0105] Advantageous use may also be made of phosphites of various di- orpolyols: e.g. tetraphenyldipropylene glycol diphosphite, polydipropyleneglycol phenyl phosphite, tetramethylolcyclohexanol decyl diphosphite,tetramethylolcyclohexanol butoxyethoxyethyl diphosphite,tetramethylolcyclohexanol nonylphenyl diphosphite, bis(nonylphenyl)di(trimethylolpropane) diphosphite, bis(2-butoxyethyl)di(trimethylolpropane) diphosphite, tris(hydroxyethyl) isocyanuratehexadecyl triphosphite, didecyl pentaerythrityl diphosphite, distearylpentaerythrityl diphosphite, bis(2,4-di-tert-butylphenyl)pentaerythrityl diphosphite, and also mixtures of these phosphites andaryl/alkyl phosphite mixtures of empirical composition(H₁₉C₉-C₆H₄O)_(1.5)P(OC_(12,13)H_(25,27))_(1.5) or[C₈H₁₇—C₆H₄—O—]₂P[i-C₈H₁₇O],(H₁₉C₉—C₆H₄O)_(1.5)P(OC_(9,11)H_(19,23))_(1.5).

[0106] Industrial examples are Naugard P, Mark CH 300, Mark CH 301, MarkCH 302, Mark CH 304 and Mark CH 55.

[0107] Examples of total amounts of the organic phosphites used, or ofmixtures thereof, are from 0.01 to 10 parts by weight, advantageouslyfrom 0.05 to 5, and in particular from 0.1 to 3 parts by weight, basedon 100 parts by weight of PVC.

[0108] Epoxidized Fatty Acid Esters and Other Epoxy Compounds

[0109] The stabilizer combination of the invention may additionally andpreferably comprise at least one epoxidized fatty acid ester. Possiblecompounds here are especially esters of fatty acids from natural sources(fatty acid glycerides), such as soya oil or rapeseed oil. However, itis also possible to use synthetic products, such as epoxidized butyloleate. Use may also be made of epoxidized polybutadiene andpolyisoprene, if desired also in a partially hydroxylated form, or ofglycidyl acrylate and glycidyl methacrylate as homo- or copolymer. Theseepoxy compounds may also have been applied to an alumino salt compound;in this connection see also DE-A-4 031 818. Examples of total amounts ofthe epoxy compounds used are preferably at least 0.1 part by weight, forexample from 0.1 to 50 parts by weight, advantageously from 1 to 30 andin particular from 1 to 25 parts by weight, based on 100 parts by weightof PVC.

[0110] Antioxidants

[0111] Alkylated monophenols, e.g. 2,6-di-tert-butyl-4-methyl-phenol,alkylthiomethylphenols, e.g. 2,4-dioctylthiomethyl-6-tert-butylphenol,alkylated hydroquinones, e.g. 2,6-di-tert-butyl-4-methoxyphenol,hydroxylated thiodiphenyl ethers, e.g.2,2′-thiobis(6-tert-butyl-4-methylphenol), alkylidenebisphenols, e.g.2,2′-methylenebis(6-tert-butyl-4-methylphenol), benzyl compounds, e.g.3,5,3′,5′-tetratert-butyl-4,4′-dihydroxydibenzyl ether,hydroxybenzylated malonates, e.g. dioctadecyl2,2-bis(3,5-di-tert-butyl-2-hydroxybenzyl) malonate, hydroxybenzylaromatics, e.g.1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-2,4,6-trimethylbenzene,triazine compounds, e.g.2,4-bisoctylmercapto-6-(3,5-di-tert-butyl-4-hydroxyanilino)-1,3,5-triazine,phosphonates and phosphonites, e.g. dimethyl2,5-di-tert-butyl-4-hydroxybenzylphosphonate, acylaminophenols, e.g.4-hydroxylauranilide, esters ofbeta-(3,5-ditert-butyl-4-hydroxyphenyl)propionic acid,beta-(5-tert-butyl-4-hydroxy-3-methylphenyl)propionic acid,beta-(3,5-dicyclohexyl-4-hydroxyphenyl)propionic acid, esters of3,5-ditert-butyl-4-hydroxyphenylacetic acid with mono- or polyhydricalcohols, amides of beta-(3,5-ditert-butyl-4-hydroxyphenyl)propionicacid, such as, for example,N,N′-bis(3,5-ditert-butyl-4-hydroxyphenyl-propionyl)hexamethylenediamine,vitamin E (tocopherol) and derivatives. Mixtures of the antioxidants mayalso be used.

[0112] Industrial examples are Naugard 10, Naugard 76, Naugard BHT andNaugard 45.

[0113] Examples of the amounts of the antioxidants used are from 0.01 to10 parts by weight, advantageously from 0.1 to 10 parts by weight and inparticular from 0.1 to 5 parts by weight, based on 100 parts by weightof PVC.

[0114] UV Absorbers and Light Stabilizers

[0115] Examples of these are: 2-(2′-hydroxyphenyl)benzo-triazoles, suchas 2-(2′-hydroxy-5′-methylphenyl)-benzotriazole, 2-hydroxybenzophenones,esters of unsubstituted or substituted benzoic acids, such as4-tert-butylphenyl salicylate, phenyl salicylate, acrylates, nickelcompounds, oxalamides, such as 4,4′-dioctyloxyoxanilide,2,2′-dioctyloxy-5,5′-ditert-butyloxanilide,2-(2-hydroxyphenyl)-1,3,5-triazines, such as2,4,6-tris(2-hydroxy-4-octyloxyphenyl)-1,3,5-triazine,2-(2-hydroxy-4-octyloxyphenyl)-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine,sterically hindered amines, such asbis(2,2,6,6-tetramethylpiperidin-4-yl) sebacate,bis(2,2,6,6-tetramethylpiperidin-4-yl) succinate. Mixtures of the UVabsorbers and/or light stabilizers may also be used.

[0116] Blowing Agents

[0117] Examples of blowing agents are organic azo compounds and organichydrazo compounds, tetrazoles, oxazines, isatoic anhydride, and alsosoda and sodium bicarbonate. Preference is given to azodicarbonamide andsodium bicarbonate and also mixtures of these.

[0118] Definitions for and examples of impact modifiers and processingaids, gelling agents, antistats, biocides, metal deactivators, opticalbrighteners, flame retardants, antifogging agents and compatibilizersare given in “Kunststoffadditive” [“Plastics Additives”], R. Gächter/H.Müller, Carl Hanser Verlag, 3rd and 4th Ed., 1989 and 2001, and in“Handbook of Polyvinyl Chloride Formulating”, E. J. Wilson, J. Wiley &Sons, 1993, and also in “Plastics Additives”, G. Pritchard, Chapman &Hall, London, 1st edition, 1998.

[0119] Impact modifiers are also described in detail in “ImpactModifiers for PVC”, J. T. Lutz/D. L. Dunkelberger, John Wiley & Sons,1992.

[0120] Use may be made of one or more additives and/or mixtures thereofmay be used.

[0121] The invention also provides compositions which comprise achlorine-containing polymer and a stabilizer system of the invention.

[0122] The invention also provides compositions which comprise achlorine-containing polymer and a stabilizer system of the invention inaddition to one or more other components from one of the groupsexemplified by glycidyl compounds, phosphites, hydrotalcites, zeolites,and alkali metal and alkaline earth metal compounds and epoxidized fattyesters.

[0123] The amounts of these compounds of the general formulae (I), (II)and (III) present for stabilization in these chlorine-containing polymercompositions are advantageously from 0.01 to 10 parts by weight,preferably from 0.05 to 5 parts by weight, in particular from 0.1 to 2parts by weight based on 100 parts by weight of PVC.

[0124] Examples of the amount used of the perchlorate compounds are from0.001 to 5 parts by weight, advantageously from 0.01 to 3 parts byweight, particularly preferably from 0.01 to 2 parts by weight, based on100 parts by weight of PVC.

[0125] The co-additives such as glycidyl compounds, phosphites,hydrotalcites, zeolites, and alkali metal and alkaline earth metalcompounds and epoxidized fatty esters are used at from 0.01 to 15 partsby weight, preferably from 0.1 to 10 parts by weight, in particular from2 to 3 parts by weight.

[0126] Examples of the chlorine-containing polymers to be stabilizedare:

[0127] polymers of vinyl chloride, of vinylidene chloride, vinyl resinswhose structure contains vinyl chloride units, such as copolymers ofvinyl chloride and vinyl esters of aliphatic acids, in particular vinylacetate, copolymers of vinyl chloride with esters of acrylic ormethacrylic acid and with acrylonitrile, copolymers of vinyl chloridewith diene compounds and with unsaturated dicarboxylic acids oranhydrides of these, such as copolymers of vinyl chloride with diethylmaleate, diethyl fumarate or maleic anhydride, postchlorinated polymersand copolymers of vinyl chloride, copolymers of vinyl chloride andvinylidene chloride with unsaturated aldehydes, ketones and others, suchas acrolein, crotonaldehyde, vinyl methyl ketone, vinyl methyl ether,vinyl isobutyl ether and the like; polymers of vinylidene chloride andcopolymers of the same with vinyl chloride and with other polymerizablecompounds; polymers of vinyl chloroacetate and of dichlorodivinyl ether;chlorinated polymers of vinyl acetate, chlorinated polymeric esters ofacrylic acid and of alpha-substituted acrylic acid; polymers ofchlorinated styrenes, such as dichlorostyrene; chlorinated rubbers;chlorinated polymers of ethylene; polymers and postchlorinated polymersof chlorobutadiene and copolymers of these with vinyl chloride,chlorinated natural or synthetic rubbers, and also mixtures of thepolymers mentioned with themselves or with other polymerizablecompounds. For the purposes of this invention, PVC includes copolymerswith polymerizable compounds, such as acrylonitrile, vinyl acetate orABS, where these may be suspension polymers, bulk polymers or elseemulsion polymers. Preference is given to a PVC homopolymer, also incombination with polyacrylates.

[0128] Other possible polymers are graft polymers of PVC with EVA, ABSor MBS. Other preferred substrates are mixtures of the abovementionedhomo- and copolymers, in particular vinyl chloride homopolymers, withother thermoplastic or/and elastomeric polymers, in particular blendswith ABS, MBS, NBR, SAN, EVA, CPE, MBAS, PMA, PMMA, EPDM or withpolylactones, in particular from the group consisting of ABS, NBR, NAR,SAN and EVA. The abbreviations used for the copolymers are familiar tothe skilled worker and have the following meanings: ABS:acrylonitrile-butadiene-styrene; SAN: styrene-acrylonitrile; NBR:acrylonitrile-butadiene; NAR: acrylonitrile-acrylate; EVA:ethylene-vinyl acetate. Other possible polymers are in particularstyrene-acrylonitrile copolymers based on acrylate (ASA). A preferredcomponent in this context is a polymer composition which comprises, ascomponents (i) and (ii), a mixture of 25-75% by weight of PVC and 75-25%by weight of the copolymers mentioned. Components of particularimportance are compositions made from (i) 100 parts by weight of PVC and(ii) 0-300 parts by weight of ABS and/or SAN-modified ABS and 0-80 partsby weight of the copolymers NBR, NAR and/or EVA, but in particular EVA.

[0129] For the purposes of the present invention it is also possible tostabilize in particular recycled materials of chlorine-containingpolymers, specifically the polymers described in more detail above,which have been degraded by processing, use or storage. Recycledmaterial from PVC is particularly preferred.

[0130] The compounds which may be used concomitantly according to theinvention, and also the chlorine-containing polymers, are well known tothe skilled worker and are described in detail in “Kunststoffadditive”[“Plastics Additives”], R. Gächter/H. Müller, Carl Hanser Verlag, 3rdand 4th Ed., 1989 and 2001; in DE 197 41 778 and in EP-A 99 105 418.0 of17.03.1999, which are incorporated herein by way of reference.

[0131] The stabilization according to the invention is particularlyadvantageous for rigid PVC formulations for transparent andnon-transparent applications, as are common in pipes, profiles andsheets. For transparent applications, use is preferably made ofcompounds of the formula (I) or (II) or (III) which have a melting pointbelow about 190° C. The stabilization is also useful for semirigid andflexible formulations, and also in plastisols. The stabilizationrequires no heavy metal compounds (Sn stabilizers, Pb stabilizers, Cdstabilizers, Zn stabilizers) and is particularly highly suitable forproducing physiologically acceptable consumer products from PVC,including products for medical use.

[0132] The stabilizer systems may advantageously be incorporated by thefollowing methods: as emulsion or dispersion; as a dry mixture duringthe mixing of added components or polymer mixtures; by direct additioninto the processing apparatus (e.g. calender, mixer, kneader, extruderor the like) or as a solution or melt or, respectively, as flakes orpellets in a dust-free form as one-pack.

[0133] The PVC stabilized according to the invention, which is alsoprovided by the invention, may be prepared in a manner known per se, byusing equipment known per se, such as the abovementioned processingapparatus, to mix the stabilizer system of the invention and, ifdesired, other additives, with the PVC. The stabilizers here may beadded individually or in a mixture, or else in the form of what areknown as masterbatches.

[0134] The PVC stabilized as in the present invention may be broughtinto the desired shape in a known manner. Examples of processes of thistype are grinding, calendering, extruding, injection moulding andspinning, and also extrusion blowmoulding. The stabilized PVC may alsobe processed to give foams.

[0135] A PVC stabilized according to the invention is, particularlysuitable for example, for hollow articles (bottles), packaging films(thermoformed films), blown films, pipes, foams, heavy profiles (windowframes), translucent-wall profiles, construction profiles, sidings,fittings, office sheeting and apparatus housings (computers, householddevices).

[0136] Preference is given to rigid PVC foam moldings and PVC pipes, forexample for drinking water or wastewater, pressure pipes, gas pipes,cable-duct pipes and cable-protection pipes, pipes for industrialpipelines, drainpipes, outflow pipes, gutter pipes and drainage pipes.For more detail in this connection see “Kunststoffhandbuch PVC”[“Plastics Handbook PVC”], Vol. 2/2, W. Becker/H. Braun, 2nd Ed., 1985,Carl Hanser Verlag, pp. 1236-1277.

[0137] The examples below illustrate the invention but do not restrictthe same. As in the remainder of the description, parts and percentagesgiven are based on weight.

EXAMPLE 1 Dehydrochlorination Test on Treated PVC Powder

[0138] The mixtures made from PVC +additives in accordance with Tables1A-5A and Table 7 below were pasted or dissolved using 150 ml ofmethanol. The mixture was then concentrated to dryness on a rotaryevaporator at reduced pressure (<50 mbar) at a bath temperature of40-45° C.

[0139] The PVC powder treated in accordance with this specification wasthen subjected to a dehydrochlorination test (DHC) at T=180° C., to DIN53381. The thermal stability test for PVC is based on the elimination ofgaseous hydrogen chloride on exposure to heat. For the purposes of thisstandard, the thermal stability of PVC is the time taken for eliminationof hydrogen chloride to bring about an irreversible chemical change onexposure to heat. The higher the DHC value found (200 μS/cm) in min, themore effective the stabilizer system in inhibiting degradation of thechlorine-containing polymer.

[0140] The results have been incorporated into Tables 1A-5A and Table 7.

EXAMPLE 2 Dehydrochlorination Test on Milled Sheets

[0141] A premix made from PVC+additives in accordance with the amountsgiven in Tables 1B-5B was rolled for 5 minutes at 180° C. on mixingrolls. Test strips of film, thickness 0.5 mm, were taken from theresultant milled sheet and subjected to a dehydrochlorination test (DHC)at T=180° C., to DIN 53381 (cf. in this connection Example 1).

[0142] The results have been incorporated into Tables 1B-5B. TABLE 1ADehydrochlorination test on treated PVC powder at 180° C. Mixture 1/11/2 1/3 1/4 1/5 1/6 1/7 1/8 Norvinyl S 100 100 100 100 100 100 100 1006775 (S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6Wessalith 1.0 1.0 P ®¹⁾ Araldit GY 1.0 1.0 250 ®²⁾ Alkamizer 1.0 1.0I ®⁴⁾ Stabilizer a) 0.1 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.20.3 0.2 0.3 0.2 0.3 0.2 2-Phenylindole DHC 82 115 123 151 96 130 104 196(200 μS/cm) in min

[0143] TABLE 1B Dehydrochlorination test on milled sheets at 180° C.Mixture 1/1 1/2 1/3 1/4 1/5 1/6 Norvinyl S 6775 100 100 100 100 100 100(S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 Loxiol G 71 S⁶⁾0.4 0.4 0.4 0.4 0.4 0.4 Wessalith P ®¹⁾ 1.0 1.0 Araldit GY 250 ®²⁾ 1.01.0 Stabilizer a) 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.2 0.3 0.20.3 0.2 2-Phenylindole DHC (200 μS/cm) in 61 93 20 155 100 179 min

[0144] It can be seen that the use of a) sodium perchlorate compound andb)2-phenylindole leads to substantially better stabilization than theuse of 2-phenylindole alone. It can also be seen that the stability canbe further increased by adding one or more additives. TABLE 2ADehydrochlorination test on treated PVC powder at 180° C. Mixture 2/12/2 2/3 2/4 2/5 2/6 2/7 2/8 Norvinyl 100 100 100 100 100 100 100 100 S6775 (S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6Wessalith 1.0 1.0 P ®¹⁾ Araldit GY 1.0 1.0 250 ®²⁾ Precal 50 1.0 1.0S ®³⁾ Alkamizer 1.0 1.0 I ®⁴⁾ Stabilizer a) 0.1 0.1 0.1 0.1 CD 36-0020⁵⁾Stabilizer b) 0.3 0.2 0.3 0.2 0.3 0.2 0.3 0.2 1,4-Butanediol bis (β-amino- crotonate) DHC 57 88 64 127 55 86 65 104 (200 μS/cm) in min

[0145] TABLE 2B Dehydrochlorination test on milled sheets at 180° C.Mixture 2/1 2/2 2/3 2/4 2/5 2/6 Norvinyl S 6775 100 100 100 100 100 100(S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 Loxiol G 71 S⁶⁾0.4 0.4 0.4 0.4 0.4 0.4 Araldit GY 250 ®²⁾ 1.0 1.0 Alkamizer I ®⁴⁾ 1.01.0 Stabilizer a) 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.2 0.3 0.20.3 0.2 1,4-Butanediol bis(β- aminocrotonate) DHC (200 μS/cm) in 40 6622 137 71 127 min

[0146] It can be seen that the use of a) sodium perchlorate compound andb)1,4-butanediol bis(β-aminocrotonate) leads to substantially betterstabilization than the use of 1,4-butanediol bis(β-aminocrotonate)alone. It can also be seen that the stability can be further increasedby adding one or more additives. TABLE 3A Dehydrochlorination test ontreated PVC powder at 180° C. Mixture 3/1 3/2 Norvinyl S 6775 (S PVC 100100 K value 67) Ca stearate 0.6 0.6 Wessalith P ®¹⁾ 1.0 1.0 Araldit GY250 ®²⁾ Precal 50 S ®³⁾ Alkamizer I ®⁴⁾ Stabilizer a) 0.1 CD 36-0020⁵⁾Stabilizer b) 0.3 0.2 Thio (diethylene glycol) bis(β- aminocrotonate)DHC (200 μS/cm) in min 63 88

[0147] TABLE 3B Dehydrochlorination test on milled sheets at 180° C.Mixture 3/1 3/2 3/3 3/4 3/5 3/6 Norvinyl S 6775 100 100 100 100 100 100(S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 Loxiol G 71 S⁶⁾0.4 0.4 0.4 0.4 0.4 0.4 Araldit GY 250 ®²⁾ 1.0 1.0 Alkamizer I ®⁴⁾ 1.01.0 Stabilizer a) 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.2 0.3 0.20.3 0.2 Thio (diethylene glycol) bis(β- aminocrotonate) DHC (200 μS/cm)in min 49 75 14 143 78 134

[0148] It can be seen that the use of a) sodium perchlorate compound andb) thio (diethylene glycol) bis(β-aminocrotonate) leads to substantiallybetter stabilization than the use of thio (diethylene glycol)bis(β-aminocrotonate) alone. It can also be seen that the stability canbe further increased by adding one or more additives. TABLE 4ADehydrochlorination test on treated PVC powder at 180° C. Mixture 4/14/2 4/3 4/4 4/5 4/6 4/7 4/8 Norvinyl S 100 100 100 100 100 100 100 1006775 (S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6Wessalith 1.0 1.0 P ®¹⁾ Araldit GY 1.0 1.0 250 ®²⁾ Precal 50 S ®³⁾ 1.01.0 Alkamizer 1.0 1.0 I ®⁴⁾ Stabilizer a) 0.1 0.1 0.1 0.1 CD 36-0020⁵⁾Stabilizer b) 0.3 0.2 0.3 0.2 0.3 0.2 0.3 0.2 N,N′- Diphenylthio- ureaDHC 39 90 55 112 40 73 46 87 (200 μS/cm) in min

[0149] TABLE 4B Dehydrochlorination test on milled sheets at 180° C.Mixture 4/1 4/2 4/3 4/4 4/5 4/6 Norvinyl S 6775 100 100 100 100 100 100(S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 Loxiol G 71 S⁶⁾0.4 0.4 0.4 0.4 0.4 0.4 Wessalith P ®¹⁾ 1.0 1.0 Araldit GY 250 ®²⁾ 1.01.0 Stabilizer a) 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.2 0.3 0.20.3 0.2 N,N′-Diphenylthio- urea DHC (200 μS/cm) in 25 54 38 100 57 122min

[0150] It can be seen that the use of a) sodium perchlorate compound andb) N,N′-diphenylthiourea leads to substantially better stabilizationthan the use of N,N′-diphenylthiourea alone. Indeed, comparison with theresults in Table 6 shows that the addition of N,N′-diphenylthiourea onits own leads to destabilization of the PVC. Only when a) sodiumperchlorate compound and b) N,N′-diphenylthiourea are used together isthere a marked improvement in the stability of the PVC. It can also beseen that the stability can be further increased by adding one or moreadditives. TABLE 5A Dehydrochlorination test on treated PVC powder at180° C. Mixture 5/1 5/2 Norvinyl S 6775 100 100 (S PVC K value 67) Castearate 0.6 0.6 Wessalith P ®¹⁾ 1.0 1.0 Araldit GY 250 ®²⁾ Precal 50S ®³⁾ Alkamizer I ®⁴⁾ Stabilizer a) 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.30.2 N-Phenylurea DHC (200 μS/cm) in 52 97 min

[0151] TABLE 5B Dehydrochlorination test on milled sheets at 180° C.Mixture 5/1 5/2 5/3 5/4 5/5 5/6 Norvinyl S 6775 100 100 100 100 100 100(S PVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 Loxiol G 71 S⁶⁾0.4 0.4 0.4 0.4 0.4 0.4 Araldit GY 250 ®²⁾ 1.0 1.0 Alkamizer I ®⁴⁾ 1.01.0 Stabilizer a) 0.1 0.1 0.1 CD 36-0020⁵⁾ Stabilizer b) 0.3 0.2 0.3 0.20.3 0.2 N-Phenylurea DHC (200 μS/cm) in 40 61 59 131 51 111 min

[0152] It can be seen that the use of a) sodium perchlorate compound andb) N-phenylurea leads to substantially better stabilization than the useof N-phenylurea alone. It can also be seen that the stability can befurther increased by adding one or more additives. A mixture composed of100.0 parts of Norvinyl S 6775 0.6 part of Ca stearate 0.4 part ofLoxiol ® G 71 S⁶⁾ 0.6 part of CH 300 phosphite⁷⁾ (ex Crompton) 1.0 partof Wessalith P/GY 250/Alkamizer I 0.1 part of CD 36-0020⁵⁾ 0.2 part oforganic stabilizer

[0153] was processed at 180° C. on mixing rolls for 5 minutes. Theresultant milled sheets were used for determination of the initialcolour of the milled sheet in the form of the Yellowness Index (YI) toASTM D-1925-70. Low YI values mean good stabilization and, respectively,initial colour.

[0154] The results are given in Table 6 below. TABLE 6 Tests with andwithout CH 300 phosphite⁷⁾ on milled sheets using the initial colour IC(YI) thermal test With phosphite HT/ Without phosphite Experiment ICExperiment HT/IC number (YI) number (YI) Additive Stabilizer 384 29.326269 40.51 — 2-Phenyl 389 33.29 6271 45.08 Wessalith P indole 390 25.056273 36.24 GY 250 385 35.84 6274 43.55 — 1,4-Butane- 391 37.08 627642.58 GY 250 diol bis (β- 392 40.21 6278 41.73 Alkamizer I amino-crotonate) 386 34.54 6279 46.34 — Thiodi- 393 35.15 6281 44.07 GY 250ethylene 394 38.38 6283 40.08 Alkamizer I glycol bis- (β-amino-crotonate) 387 8.38 6284 17.54 — N,N′-di- 395 9.36 6286 17.49 WessalithP phenylthio- 396 8.77 6288 13.51 GY 250 urea 388 22.19 6289 37.99 —N-phenyl- 397 22.36 6291 39.52 GY 250 urea 398 30.39 6293 39.08Alkamizer I

[0155] It is apparent that addition of phosphites can give a yet furtherrise in initial-colour-based stabilization of the chlorine-containingpolymer, using organic stabilizers in combination with a sodiumperchlorate formulation. TABLE 7 Comparative ExperimentDehydrochlorination test on treated PVC powder at 180° C. Mixture 7/17/2 7/3 7/4 7/5 7/6 7/7 7/8 Norvinyl S 100 100 100 100 100 100 100 1006775 (SPVC K value 67) Ca stearate 0.6 0.6 0.6 0.6 0.6 0.6 0.6 0.6Wessalith 1.0 1.0 p ®¹⁾ Araldit GY 1.0 1.0 250 ®²⁾ Precal 50 S ®³⁾ 1.01.0 Alkamizer 1.0 1.0 I ®⁴⁾ Stabilizer a) 0.1 0.1 0.1 0.1 CD 36-0020⁵⁾DHC 56 71 67 96 57 60 67 87 (200 μS/cm) in min

[0156] It can be seen that the use of a) sodium perchlorate compoundalone leads to only very slight improvements in stability compared withthe stability without addition of any stabilizer.

1. Stabilizer system for stabilizing halogen-containing polymers,comprising at least a) one perchlorate salt and b) at least one or moreenamines where the enamines have the formula (I)

where n=1 or 2 and X═O or NR¹, n=3-6 and X═O; R¹═H, C₁-C₄-alkyl,C₂-C₆-alkenyl, C₆-C₁₀-aryl, C₇-C₁₈-alkaryl or C₇-C₁₈-aralkyl; R² (forn=1)=C₁-C₂₂-alkyl, C₂-C₂₂-alkenyl or aryl, preferably phenyl, whereappropriate substituted with up to 3 hydroxyl, C₁-C₄-alkoxy orC₁-C₉-alkyl; or R² (for n=2-6)=linear or branched C₁₋₂₂-alkylene, whereappropriate interrupted by one or more O atoms or S atoms, where R² (forn=3) may also be C₂-C₃-alkyl-trisubstituted isocyanurate; and if X═NH,R² may also be H:
 2. Stabilizer system according to claim 1, where theperchlorate salt is a compound of the formula M(ClO₄)_(n), where M isLi, Na, K, Mg, Ca, Sr, Ba, Zn, Al, La or Ce; and n is 1, 2 or 3,depending on the valency of M.
 3. Stabilizer system according to claim 1or 2, where in the compound having the general formula (I) R¹=methyl orphenyl and X=oxygen.
 4. Stabilizer system according to any of claims 1to 3, where, in the perchlorate salt, M=Na or K and n=1.
 5. Stabilizersystem according to any of claims 1 to 4, where the compounds of thegeneral formula (I) are 1,4-butanediol bis(β-aminocrotonate) orthio(diethylene glycol) bis(β-aminocrotonate).
 6. Stabilizer systemaccording to any of claims 1 to 5, which also, where appropriate,comprises metal soaps and/or, where appropriate, comprises at least oneor more other substances from the groups consisting of the polyols anddisaccharide alcohols, glycidyl compounds, hydrotalcites, alkalimetal/alkaline earth metal aluminosilicates, alkali metal/alkaline earthmetal hydroxides, alkaline earth metal oxides or alkaline earth metal(hydrogen)carbonates, or metal carboxylates, phosphites, plasticizers,antioxidants, fillers, pigments, light stabilizers, lubricants andepoxidized fatty esters.
 7. Composition comprising a chlorine-containingpolymer and a stabilizer system according to any of claims 1 to
 6. 8.Composition according to claim 7, characterized in that, based on 100parts by weight of chlorine-containing polymer, there are from 0.01 to10 parts by weight of the compounds of the general formula (I) and/or(II) and/or (III) and from 0.001 to 5 parts by weight of the perchloratesalt.
 9. Composition according to claim 8, characterized in that, basedon 100 parts by weight of chlorine-containing polymer, from 0.01 to 10parts by weight of the compounds of the general formula (I) and 0.001 to5 parts by weight of the perchlorate salt are present.
 10. Process forstabilizing chlorine-containing polymers by adding a stabilizer systemaccording to any of claims 1 to 7 [sic] to the chlorine-containingpolymer.
 11. Consumer products comprising PVC which has been stabilizedby a stabilizer system according to any of claims 1 to 7 [sic]. 12.Stabilizer system for stabilizing halogen-containing polymers,comprising at least a) one perchlorate salt of the formula M(ClO₄)_(n),where M is Li, Na, K, Mg, Ca, Sr, Ba, Zn, La or Ce; and n is 1, 2 or 3,depending on the valency of M; and b) at least one or more indolederivatives, where the indole derivatives have the general formula (II)

where m=0, 1, 2 or 3; R³=C₁-C₁₈-alkyl, C₂-C₁₈-alkenyl, C₆-C₁₀-aryl or

C₇-C₂₄-alkaryl, C₇-C₁₀-aralkyl or C₁-C₄-alkoxy; R⁴, R⁵═H, C₁-C₄-alkyl,or C₁-C₄-alkoxy.
 13. Stabilizer system according to claim 12, where inthe compound having the general formula (II) R³=phenyl.
 14. Stabilizersystem according to claim 12 or 13, where, in the perchlorate salt, M=Naor K and n=1.
 15. Stabilizer system according to any of claims 12 to 14,where the compounds of the general formula (II) are 2-phenylindole or2-phenyllaurlindole.
 16. Stabilizer system according to any of claims 12to 15, which also, where appropriate, comprises metal soaps and/or,where appropriate, comprises at least one or more other substances fromthe groups consisting of the polyols and disaccharide alcohols, glycidylcompounds, hydrotalcites, alkali metal/alkaline earth metalaluminosilicates, alkali metal/alkaline earth metal hydroxides, alkalineearth metal oxides or alkaline earth metal (hydrogen)carbonates, ormetal carboxylates, phosphites, plasticizers, antioxidants, fillers,pigments, light stabilizers, lubricants and epoxidized fatty esters. 17.Stabilizer system according to any of claims 12 to 16, where a phosphiteis also present and/or possible reaction products of phosphite withcomponents a) and/or b) are also present.
 18. Composition comprising achlorine-containing polymer and a stabilizer system according to any ofclaims 12 to
 17. 19. Composition according to claim 18, characterized inthat, based on 100 parts by weight of chlorine-containing polymer, thereare from 0.01 to 10 parts by weight of the compounds of the generalformula (II) and from 0.001 to 5 parts by weight of the perchloratesalt.
 20. Process for stabilizing chlorine-containing polymers by addinga stabilizer system according to any of claims 12 to 17 to thechlorine-containing polymer.
 21. Consumer products comprising PVC whichhas been stabilized by a stabilizer system according to any of claims 12to 17.